I have a Denon avr-1913 and my cable box, BD, and xbox are all hooked up to the tv with one hdmi wire. Can I hook up my sound bar through the TV or do I have to run it through the denon receiver. Right now I am getting no sound by running it through TV with optical cable.

Why are you wanting to use a powered soundbar with an AVR? They really aren't meant to go together. That said there are a couple things you could try that may or may not work.

I assume you mean you have your source devices connected to the Denon. Try taking the HDMI output from the Denon and connecting it as input to the soundbar. Then a second HDMI out from the soundbar to your TV.

Or you could try leaving your current connections in place, change the audio output setting on the Denon to "TV", then connect an optical cable from your TV to the soundbar and change your TV speaker setting to "external".

Why didn't you just get speakers or a passive soundbar. You'd likely have much better SQ that way.